Parental transmission of type 2 diabetes mellitus in a highly endogamous population

Environment driven changes in type 2 diabetes, overweight and obesity in an isolated Mixe community in the Valley of Oaxaca, southern Mexico

BACKGROUND

This study focused on type 2 diabetes mellitus (T2DM) in a group of adult Mixe, an Indigenous population from Oaxaca, Mexico. Mixe comprised an estimated 9.4% (n ≅ 90 000) of the Indigenous population in Oaxaca. Mexico.

OBJECTIVE

This study focused on a group of adult Mixe, an Indigenous population from Oaxaca, Mexico. To compare the prevalence of T2DM, overweight (OW), obesity (OB), and hypertension (HTN) between 2007 and 2017 for a small, isolated Mixe community in the Valley of Oaxaca, Mexico. We test whether or not environmental changes have affected T2DM prevalence.

METHODS AND MATERIALS

Demographic and medical record data were collected in the community in 2007 and 2017 from the medical clinic and the mayor's office. T2DM was medically diagnosed among adults (>34 years old), in 2007 (n = 730) and in 2017 (n = 829).

RESULTS

T2DM crude prevalence increased from 6.7% to 12.1% (p < .001) from 2007 to 2017. The mean age of the sample analyzed was 60.6 (SD = 9.7). Age-adjusted T2DM prevalence increased from 6.7% to 10.8% (p < .002). T2DM was 5.7%-5.5% among males (p < .53) and 7.1%-13.6% among females (p < .001). Sex-specific OW and OB simulation studies indicate females had 7% less OW in 2007, and males were unchanged compared with 2017. OB among males and females was significantly higher in 2017 compared with 2007 (increased by 15.2% and 8.3%, males and females, respectively). Sexes combined OW + OB increased 12.7% among males but was unchanged in females (-0.5%). In the sexes combined analysis, OW prevalence increased 12.7% to 27.1% (p < .001) and OB prevalence increased 10.7%-27.9% (p < .001) from 2007 to 2017. HTN did not change significantly from 2007 to 2017 (15.4% and 14.6%, respectively) (p = .63) in adults. Among T2DM individuals, the frequency of HTN was not significantly different in 2007 and 2017 (57.1% and 37%, respectively) (p = .65). Transition to a Western diet consisting of high-carbohydrate foods occurred at the same time as increased T2DM from 2007 to 2017, with a higher prevalence of T2DM noted among females in 2017.

CONCLUSIONS

An increased prevalence of T2DM, OW, and OB but not HTN was observed in the Mixe community from 2007 to 2017 and was associated with the adoption of a high-carbohydrate Western diet.

The value of parental medical records for the prediction of diabetes and cardiovascular disease: a novel method for generating and incorporating family histories

OBJECTIVE

To determine whether data-driven family histories (DDFH) derived from linked EHRs of patients and their parents can improve prediction of patients' 10-year risk of diabetes and atherosclerotic cardiovascular disease (ASCVD).

MATERIALS AND METHODS

A retrospective cohort study using data from Israel's largest healthcare organization. A random sample of 200 000 subjects aged 40-60 years on the index date (January 1, 2010) was included. Subjects with insufficient history (<1 year) or insufficient follow-up (<10 years) were excluded. Two separate XGBoost models were developed-1 for diabetes and 1 for ASCVD-to predict the 10-year risk for each outcome based on data available prior to the index date of January 1, 2010.

RESULTS

Overall, the study included 110 734 subject-father-mother triplets. There were 22 153 cases of diabetes (20%) and 11 715 cases of ASCVD (10.6%). The addition of parental information significantly improved prediction of diabetes risk (P < .001), but not ASCVD risk. For both outcomes, maternal medical history was more predictive than paternal medical history. A binary variable summarizing parental disease state delivered similar predictive results to the full parental EHR.

DISCUSSION

The increasing availability of EHRs for multiple family generations makes DDFH possible and can assist in delivering more personalized and precise medicine to patients. Consent frameworks must be established to enable sharing of information across generations, and the results suggest that sharing the full records may not be necessary.

CONCLUSION

DDFH can address limitations of patient self-reported family history, and it improves clinical predictions for some conditions, but not for all, and particularly among younger adults.

Consanguinity and Diabetes in Saudi Population: A Case-Control Study

BACKGROUND AND AIM

Diabetes mellitus (DM) of both types is a genetically determined disorder and is prevalent in the Saudi population. Furthermore, the rate of consanguineous marriages is also high among Saudis. Therefore, we aimed to determine the prevalence of consanguinity among people with DM and investigate the effect of consanguinity on the occurrence of diabetes at different levels.

METHODS

A descriptive cross-sectional study was carried out at the Obesity, Metabolism and Endocrine Center of King Fahad Medical City in Riyadh, Saudi Arabia in January 2021. Information on patients' demographics (age, gender), family history of DM, and presence of consanguinity, and degree of consanguineous marriage were collected.

RESULTS

We included 324 people with DM, 143 (44.1%) with type 1 diabetes (T1DM), and 181 (55.9%) with type 2 diabetes (T2DM). We included 201 people without DM for T1DM control and 300 people for T2DM control. The mean age was 26.6 ± 11.1 years for the T1DM group and 57.8 ± 11.6 years for the T2DM group. Consanguinity was noted among 73 (51.4%) T1DM patients, but T1DM was not significantly related to consanguinity. T2DM was significantly correlated with consanguinity (r=0.132, p=0.004) particularly among patients with a degree of consanguinity as first-cousins for both paternal and maternal sides (odds ratio [OR]=1.151 and 1.476). Gender and positive family history for DM and consanguineous marriage between cousins were significant factors for T2DM. After controlling for gender and a positive family history of DM, consanguineous marriage between cousins from both the paternal and maternal sides remained significant.

CONCLUSION

T2DM occurrence increases in presence of consanguinity in the Saudi population. This relationship might contribute to the higher risk of DM prevalence. Further studies are needed to elucidate this relationship deeply. It's unclear whether lowering consanguineous marriages would decrease the prevalence of diabetes or not. However, a clear message about this correlation has to be delivered to the public.

Generalizability of GWA-Identified Genetic Risk Variants for Metabolic Traits to Populations from the Arabian Peninsula

The Arabian Peninsula, located at the nexus of Africa, Europe, and Asia, was implicated in early human migration. The Arab population is characterized by consanguinity and endogamy leading to inbreeding. Global genome-wide association (GWA) studies on metabolic traits under-represent the Arab population. Replicability of GWA-identified association signals in the Arab population has not been satisfactorily explored. It is important to assess how well GWA-identified findings generalize if their clinical interpretations are to benefit the target population. Our recent study from Kuwait, which performed genome-wide imputation and meta-analysis, observed 304 (from 151 genes) of the 4746 GWA-identified metabolic risk variants replicable in the Arab population. A recent large GWA study from Qatar found replication of 30 GWA-identified lipid risk variants. These complementing studies from the Peninsula increase the confidence in generalizing metabolic risk loci to the Arab population. However, both the studies reported a low extent of transferability. In this review, we examine the observed low transferability in the context of differences in environment, genetic correlations (allele frequencies, linkage disequilibrium, effect sizes, and heritability), and phenotype variance. We emphasize the need for large-scale GWA studies on deeply phenotyped cohorts of at least 20,000 Arab individuals. The review further presents GWA-identified metabolic risk variants generalizable to the Arab population.

Parental consanguinity among patients with schizophrenia in a rural community of South India: A clinical and genetic investigation

BACKGROUND

Studies from certain regions of the world indicate that consanguineous marriages are a risk factor for the development of schizophrenia in offspring. However the evidence is inconsistent partly due to methodological limitation of which hospital based recruitment contributing to significant bias. The studies from the Indian subcontinent, is scarce, where rates of consanguinity is high.

METHODS

The schizophrenia patients living in a geographically defined rural south Indian community and randomly selected controls dwelling in the same community sharing sociocultural, economic and lifestyle factors were recruited. They were assessed for parental consanguinity using the clinical interviews as well as DNA-based estimates. The latter was conducted by calculating the coefficient of inbreeding 'f'. A participant was considered to have consanguineous parentage if his/her parents shared a common ancestor no more remote than a great-great-grandparent, corresponding to DNA-based estimates of 'f' ≥ 0.0156.

RESULTS

The rates of parental consanguinity assessed by clinical interview were comparable in both groups (Cases: 10.71 %, Controls: 7.25 %; χ² = 0.493, p = 0.4825). However, DNA-based rates of parental consanguinity showed that 'f' was significantly higher among cases than controls (Mann-Whitney U = 11315.5; p = 0.022). Seventy-five cases (62.5 %) and 108 control participants (48.6 %) had 'f' ≥ 0.0156 (χ² = 6.008; p = 0.014). The results were consistent across different quality control measures.

CONCLUSION

Schizophrenia is associated with higher parental consanguinity, suggesting a role for multiple recessive risk alleles in its etiology. Replication in future studies in diverse settings would add further strength to this.

Identification of Maturity-Onset-Diabetes of the Young (MODY) mutations in a country where diabetes is endemic

Genetic variants responsible for Maturity-Onset-Diabetes of the Young (MODY) in Kuwait were investigated. A newly established a National Referral Clinic, the Dasman Diabetes Institute (DDI-NRC), assessed forty-five members from 31 suspected MODY families by whole exome sequencing. Thirty-three of the 45 samples were independently sequenced at the DDI-NRI, Exeter University, UK (https://www.diabetesgenes.org/) using targeted 21-gene panel approach. Pathogenic mutations in GCK, HNF1A, HNF1B, HNF4A, and PDX1 confirmed MODY in 7 families, giving an overall positivity rate of 22.6% in this cohort. Novel variants were identified in three families in PDX1, HNF1B, and HNF1B. In this cohort, Multiplex Ligation-dependent Probe Amplification assay did not add any value to MODY variant detection rate in sequencing negative cases. In highly selected familial autoantibody negative diabetes, known MODY genes represent a minority and 77.3% of the familial cases have yet to have a causal variant described.

Maternal and paternal histories differentially influence risks for diabetes, insulin secretion and insulin resistance in a Chinese population

Aims/Introduction

To investigate the differential effects of maternal versus paternal history of diabetes on the risks for diabetes and prediabetes, as well as on insulin secretion and resistance in Chinese individuals.

Materials and Methods

From the 2007 to 2008 China National Diabetes and Metabolism Disorders Study, 39,244 participants were included and divided into four categories: negative parental history, paternal history only (PH), maternal history only (MH), and both paternal and maternal history.

Results

The age‐ and sex‐standardized prevalence rates of diabetes in the negative parental history, PH, MH, and both paternal and maternal history groups were 8.59, 12.56, 15.86 and 29.81%, respectively. The prevalence rates of impaired glucose metabolism were 24.13, 25.41, 31.13 and 50.80%, with the prevalence in the MH group being significantly higher than that in the PH group. Compared with that in the FH0 group, the risks of diabetes in the PH, MH, and both paternal and maternal history groups were 2.01‐, 2.67‐ and 6.37‐fold greater, and the risks of impaired glucose metabolism were 1.28‐, 1.65‐ and 3.45‐fold greater. In addition, MH had a significantly greater impact on impaired glucose metabolism than PH (P_MHvsPH = 0.0292). Regression analyses suggested MH was associated with homeostatic model assessment for β‐cell function (β[SE] = −0.0910[0.0334], P = 0.0065), insulinogenic index (−0.1866[0.0550], P = 0.0007), homeostatic model assessment for insulin resistance (0.0662[0.0227], P = 0.0036) and Matsuda Index [−0.0716(0.0203), P = 0.0004]. PH was specifically associated with homeostatic model assessment for insulin resistance (0.1343[0.0267], P < 0.0001) and Matsuda Index (−0.1566[0.0243], P < 0.0001), but the effects were stronger than those of MH (P_MHvsPH = 0.0431, 0.0054).

Conclusions

MH and PH differentially influence the risks for diabetes, insulin secretion, and insulin resistance in the Chinese population, suggesting they participate in the pathogenesis of diabetes through different mechanisms.

Maternal vs paternal diabetes: The parental history is different in younger onset versus older onset type 2 diabetes

BACKGROUND

A number of previous studies exploring family history of type 2 diabetes have reported a predominance of maternal diabetes. These studies have not explicitly compared parental history of diabetes across the spectrum of disease onset from youth to later adulthood.

METHODS

Family history data from 11,467 patients with type 2 diabetes were extracted from the RPA Diabetes Centre database. Parental histories of diabetes were compared across a range of age of diagnosis strata (15-<30, 30-<40, 40-<50, 50-<60 and 60-<70 years). For the young-onset group (diagnosed between 15 and 30 years of age), associations between parental history of diabetes and the presence of cardio-metabolic risk factors and diabetic complications were also explored.

RESULTS

For the total cohort and within each age of diagnosis strata, more individuals reported maternal history than paternal history of diabetes. The young-onset group demonstrated the highest prevalence of any parental history of diabetes (60.7%), the highest combined maternal and paternal history (15.8%) and the smallest differential between maternal (25.1%) and paternal (19.7%) history of diabetes. Within the young-onset group, no significant association between parental history and cardio-metabolic risk factors or diabetic complications were identified after a median of 15.0 years of diabetes exposure.

CONCLUSION

Overall, our results demonstrate a consistent maternal excess of diabetes which could be consistent with an underlying epigenetic effect. However, the differential between maternal and paternal history is significantly lower in the young-onset group. Earlier emergence of type 2 diabetes may therefore reflect a different interaction and impact of genetic and environmental factors.

A Perception on Genome-Wide Genetic Analysis of Metabolic Traits in Arab Populations

Despite dedicated nation-wide efforts to raise awareness against the harmful effects of fast-food consumption and sedentary lifestyle, the Arab population continues to struggle with an increased risk for metabolic disorders. Unlike the European population, the Arab population lacks well-established genetic risk determinants for metabolic disorders, and the transferability of established risk loci to this population has not been satisfactorily demonstrated. The most recent findings have identified over 240 genetic risk loci (with ~400 independent association signals) for type 2 diabetes, but thus far only 25 risk loci (ADAMTS9, ALX4, BCL11A, CDKAL1, CDKN2A/B, COL8A1, DUSP9, FTO, GCK, GNPDA2, HMG20A, HNF1A, HNF1B, HNF4A, IGF2BP2, JAZF1, KCNJ11, KCNQ1, MC4R, PPARγ, SLC30A8, TCF7L2, TFAP2B, TP53INP1, and WFS1) have been replicated in Arab populations. To our knowledge, large-scale population- or family-based association studies are non-existent in this region. Recently, we conducted genome-wide association studies on Arab individuals from Kuwait to delineate the genetic determinants for quantitative traits associated with anthropometry, lipid profile, insulin resistance, and blood pressure levels. Although these studies led to the identification of novel recessive variants, they failed to reproduce the established loci. However, they provided insights into the genetic architecture of the population, the applicability of genetic models based on recessive mode of inheritance, the presence of genetic signatures of inbreeding due to the practice of consanguinity, and the pleiotropic effects of rare disorders on complex metabolic disorders. This perspective presents analysis strategies and study designs for identifying genetic risk variants associated with diabetes and related traits in Arab populations.

Burden of diabetes mellitus attributable to demographic levels in Qatar: an emerging public health problem

BACKGROUND

Diabetes is one of the main contributors to ill health and premature mortality worldwide and its prevalence has been rising during the last decades.

AIM

The aim of the present study was to quantify the burden of disease in terms of deaths and loss of healthy life years (DALYs) attributed to diabetes by its demographic levels in the State of Qatar.

MATERIALS AND METHODS

The methods were largely based on the established Global Burden of Disease methodology and use the burden of disease in terms of disability adjusted life years (DALYs) and the years lost due to disability (YLD) as the outcome measure. We calculated years lost due to disability (YLD) and years life lost (YLL) attributable to diabetes. The study was conducted during the period from June 2013 to January 2014.

RESULTS

The study findings revealed that disability adjusted life years (DALYs) has been increasing across the years and reached to 4.35 in 2011 from 2.58 in 2007. DALYs for men was remarkably higher than women during the period (2007-2011). Diabetes mellitus was the 6th leading cause of disease burden in Qatar (3.8%). The YLD showed a sharp increase in men (2.52 in 2011 from 1.34 in 2007) and women (1.05 in 2011 from 0.33 in 2007) during the year 2011. YLL portion of women enlarged considerably in 2011 (0.10) compared to 2010 (0.04). YLL for men and women was fluctuating across the years with a decrease in 2011 (18%) from 2007 (35%). Men and women in the age group 30-44 years had the highest peak across the years.

CONCLUSION

The study findings revealed that diabetes disease burden was considerably high in Qatar, particularly in the working age group. DALYs has been increasing across the years.

Adolescent prediabetes in a high-risk Middle East country: a cross-sectional study

Objective

To estimate the prevalence of prediabetes in adolescents living in a high-risk country and to detect risk factors associated with this disorder.

Design

Survey questionnaire combined with physical measurements and blood sugar determination.

Setting

Doha, capital city of Qatar.

Participants

A total of 1694 male and female students aged 11–18 years without previously diagnosed diabetes enrolled in four schools.

Main outcome measure

Blood sugar measurements. Other measured variables included gender, height, weight, abdominal circumference, country of origin, family history of diabetes and frequency of exercise.

Results

Using a random blood sugar ≥7.8 mmol/L or a fasting blood sugar ≥5.5 mmol/L as cutpoints, we identified 4.2% of students (56 boys, 15 girls) as probable prediabetics. In a multivariate model, being boys (OR 3.2, 95% CI 1.7–6.2), having a diabetic parent (OR 1.9, 95% CI 1.1–3.2) or having a waist-to-height ratio >0.5 (OR 1.8, 95% CI 1.1–3.0) were significantly associated with being a prediabetic. The parental origin of diabetes had a differential effect upon blood sugar. The mean random blood sugar in students with a maternal inheritance pattern of diabetes was 5.61 mmol/L ± 1.0, compared to 5.39 mmol/L ± 0.89 in students with a paternal inheritance pattern (p = 0.02).

Conclusions

In a country with a high risk of adult diabetes, we identified 4.2% of students aged 11–18 as being prediabetic. Risk factors associated with prediabetes included male gender, family history of diabetes and waist-to-height ratio >0.5.

The potential impact of family history of metabolic syndrome and risk of type 2 diabetes mellitus: In a highly endogamous population

AIM

This study aims to determine the potential impact of positive family history of Metabolic Syndrome (MetS) among two generations, on developing Type 2 Diabetes Mellitus (T2DM) and the potential relation of consanguineous marriage among patients with MetS to the risk of developing T2DM among a sample of Qataris.

DESIGN

A cross-sectional study.

SETTING

Primary healthcare (PHC) centers.

MATERIALS AND METHODS

The survey and measurement were conducted from April 2011 to December 2012 among Qatari nationals above 20 years of age. Of the 2,182 subjects, who were approached to participate in the study, 1,552 (71%) gave their consent. Face-to-face interviews were conducted using a structured questionnaire followed by anthropometric measurements and laboratory tests. Metabolic syndrome was defined using the National Cholesterol Education Program-Third Adult Treatment Panel (ATP III) as well as International Diabetes Federation (IDF).

RESULTS

Overall, the prevalence of MetS was 26.2% according to ATP III and 36.9% according to IDF (P < 0.0001). The mean age of MetS patients with T2DM was significantly higher than those without T2DM (Mean 48 ± 9.9 vs. 42.5 ± 9.2; P < 0.001). The proportion of females was higher among MetS patients with T2DM as compared to those without T2DM (61% vs. 51%; P = 0.053). In addition, there were significant differences between MetS patients with and without DM in terms of co-morbidities of hypertension, coronary heart disease, and high cholesterol. The proportion of MetS patients with positive family history for MetS was significantly higher in MetS patients with T2DM as compared to those without T2DM (46.7% vs. 33.8%; P = 0.009). The proportion of positive family history of MetS among fathers (35% vs. 21.9%; P = 0.005), mothers (30.5% vs. 18.8%; P = 0.008), maternal aunt (18.3% vs. 11.2%; P = 0.055), and maternal grand father (19.5% vs. 10%; P = 0.010) were significantly higher in MetS patients with T2DM as compared to the counterpart. The proportion of consanguineous marriages was almost two times higher among MetS patients with T2DM as compared to those without T2DM (80.9% vs. 41.9%; P < 0.001). The proportion of MetS patients with T2DM was lower than MetS patients without DM below 45 years, but after 45 years, the proportion of MetS patients with T2DM remained higher than their counterparts.

CONCLUSION

Family history of MetS among parents, maternal aunt, maternal grandfather, and consanguineous marriages among patients of MetS are significantly associated with the development of T2DM in Qatar. These results support the necessity of earlier screening for T2DM among MetS patients with positive family history of MetS.

Familial Clustering of Type 2 Diabetes among Omanis

OBJECTIVE

The aim of this study was to screen Omani individuals for the familial aggregation of type 2 diabetes mellitus.

METHODS

A random cohort of 1182 Omani individuals visiting the Family Medicine Clinic at Sultan Qaboos University Hospital (SQUH), Muscat, Oman, for regular medical checkup, aged ≥40 years, were sampled. Patients were categorized into three groups: (1) individuals who claim not to have diabetes and had no family history of diabetes; (2) individuals who claim not to have diabetes but had family history of diabetes; (3) individuals with diabetes. Only 16% of these Omani individuals had no diabetes and no family history of diabetes. Another separate random cohort of 234 Omani type 2 diabetes mellitus patients, from the Diabetes Clinic at SQUH, were interviewed and questioned about their family history of type 2 diabetes mellitus.

RESULTS

Ninety five percent of the patients had a family history of diabetes. Eighty percent had first degree relatives with diabetes and 46% had second degree relatives with diabetes. At least one parent with diabetes was reported among 55% of these diabetics, while maternal diabetes (55%) was found to be higher than paternal diabetes (47%). However, only 15% had both parents with diabetes. Furthermore, almost half of the 234 diabetics were having at least one of the following relatives with diabetes: brother, sister, aunt or an uncle.

CONCLUSION

The findings of this study confirm familial aggregation of diabetes among the Omani population. Compared to other populations, familial aggregation of type 2 diabetes mellitus among Omanis is relatively very high, and is perhaps due to the very high degree of consanguinity among Omanis. Since almost everyone seems to have a genetic predisposition to diabetes, the dramatic lifestyle changes over the past 25 years, could tip the population into an epidemic of type 2 diabetes mellitus.

Type 2 diabetes family histories, body composition and fasting glucose levels: a cross-section analysis in healthy sedentary male and female

BACKGROUND

Diabetes type 2 is a world wide spread disease with a multifactorial pathogenetic evolution. Various factors like obesity, physical inactivity and poor lifestyle habits contribute to its development. The aim of this study was to verify if in young healthy sedentary male and female there is positive correlation between family history to type 2 diabetes and an increase in body weight and fat mass, or alterations in basal glycemia values.

METHODS

Totally183 male and 237 female healthy sedentary subjects were analysed in 2012, in Italy. They were divided in three groups: FH(+) with first degree family history, FH(++) with second degree family history and FH(-) with no family history. Anthropometrics, body composition and blood parameters were assessed.

RESULTS

Male had the highest BMI values (P<0.01). FH(+) and FH(++) had increased waist and hip circumferences and body weight (P<0.005 for men, P<0.0001 for women), body mass index (P< 0.0001 in both sexes), waist-hip ratio (P< 0.05 for men and women) and triceps skinfold (P< 0.0005 for both sexes). Obesity incidence was higher in FH(+) and FH(++) compared to control groups.

CONCLUSIONS

The study confirms family history to diabetes type 2 as a risk factor for the development of the illness, mainly in a case of first degree of FH. Preventive interventions are necessary to promote significant life-style changes, such as increased physical activity and controlled quantity and quality of food intake.